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I'm rebuilding a Julius Bauer grand that has an odd characteristic I've seen only a few times in 40 years of rebuilding: The ribs are glued to the top of the soundboard, instead of the normal glued-to-the-underside configuration. I wondered if anyone knew some history about which piano makers first invented/used this top-rib configuration, and what they thought was the advantage gained. Obviously, any advantage must have been insignificant, as no modern pianos continued the practice, and at first glance, it seems to be counterproductive to the concept of holding the soundboard in its upwards crowned shape. Anybody know the history & purpose of this top-rib experiment?

I'm rebuilding a Julius Bauer grand that has an odd characteristic I've seen only a few times in 40 years of rebuilding: The ribs are glued to the top of the soundboard, instead of the normal glued-to-the-underside configuration. I wondered if anyone knew some history about which piano makers first invented/used this top-rib configuration, and what they thought was the advantage gained. Obviously, any advantage must have been insignificant, as no modern pianos continued the practice, and at first glance, it seems to be counterproductive to the concept of holding the soundboard in its upwards crowned shape. Anybody know the history & purpose of this top-rib experiment?

I don’t know the full history of the design. The earliest reference I’ve seen is an 1885 patent (US 320264 A) issued to John R. Lomas (with half being assigned to B. Shoninger). This patent very simply describes a soundboard assembly with superimposed ribs on both sides of the soundboard panel just as was later used by Bauer.

I’ve only seen this soundboard design used on Julius Bauer pianos. No modification of this patent was ever issued to [William M.] Bauer for the invention so I assume JB used it as described. It seems to be used in the 1914 patent (US 1171921 A) issued to Bauer for his string frame and adjustable bearing mechanism although Bauer makes no special claims for the soundboard in this patent. Both grand and vertical JB pianos used the feature.

I owned a 9’ JB grand with all of their bells and whistles for a while. Fascinating instrument. Heaviest 9’ piano I’ve ever seen—David Rubenstein’s 12’ piano is heavier but not by much.

The (claimed) advantages were crown stability and lighter weight. For a given amount of overall soundboard stiffness the combined weight of the two superimposed ribs could somewhat less than that of a traditional single ribs used in conventional soundboard design.

Essentially this systems acts like a three-ply laminate with the crown being formed during the press cycle. Compared to conventional soundboard systems the crown in these systems was absolutely stable. I monitored string bearing on my piano in Sacramento, California (hot and dry in the summer) and in Jonesboro, Arkansas (hot and humid in the summer and cold and humid in the winter). I don’t recall it ever changing. If it had it would have given me an excuse to play around with the crown-adjusting mechanism built into the piano.

The advantage was crown stability and lighter weight. The two superimposed ribs were both somewhat lighter than the traditional single ribs used in conventional soundboard design. Crown was absolutely stable.

- What made the Bauer grand the heaviest ever? More wood beams? Different plate design? In an old Bauer promotional catalogue, they bragged that its structure was so much more stable that they actually needed less beams and less square inches of plate w/more open spaces.You'd think it would end up being lighter.

- What, and where, is this crown-adjusting mechanism you speak of? Was it only on 7' or 9' models. The one I'm rebuilding is a 6 footer.

As for sandwiching the board between top & bottom ribs, my customer actually asked a smart question which was, wouldn't that be somewhat more restrictive to the free-floating vibrations of the soundboard, compared to boards with ribs on bottom only? Wouldn't it kind of clamp down and make for a thinner resonance?

— What made the Bauer grand the heaviest ever? More wood beams? Different plate design? In an old Bauer promotional catalogue, they bragged that its structure was so much more stable that they actually needed less beams and less square inches of plate w/more open spaces. You'd think it would end up being lighter.

My piano had no bellybracing at all. The weight was primarily in the string frame. It had the most complex and massive casting I’ve ever seen in a piano. Grand or vertical.

[quote}— What, and where, is this crown-adjusting mechanism you speak of? Was it only on 7' or 9' models. The one I'm rebuilding is a 6 footer. [/quote]Look up the patent (just do a Google patent search). The patent drawings explain it better than I could.

Quote:

As for sandwiching the board between top & bottom ribs, my customer actually asked a smart question which was, wouldn't that be somewhat more restrictive to the free-floating vibrations of the soundboard, compared to boards with ribs on bottom only? Wouldn't it kind of clamp down and make for a thinner resonance?

Not really. It’s the overall stiffness of the system that we’re interested in. I made no effort to measure this in my piano but I did note that the ribs—combined—were about half that of a normal rib. I.e., each rib was probably one-fourth the height of a typical rib in a conventional soundboard system. My 9’ JB was a very nice sounding piano.

I’d leave the soundboard alone. Clean it up and, if the finish has deteriorated, you might consider refinishing it. But it’s highly unlikely that—unless the ribs are delaminating from the panel or something—it will need anything more than this.

I rebuilt my piano in the early 1980s and sold it shortly thereafter. Were I doing the job today I’d do more measuring and testing. It was one of the most interesting pianos I’ve ever owned.

Again thanks for great info Del. Olek & A443 want photos. Don't know if you have any from your old 9' you can post. I'll post some of the 6-footer I'm rebuilding later this week, it's being moved into my shop on Friday.

The thought that kept coming to me as I worked on my 9' JB went something along the lines of, "I'd sure like to have seen the look on the pattern maker's and foundrymen's faces when they first saw the design of that string frame." In mine, if memory serves, it was a two-part casting.

Del, do you recall the purpose of the "rib-like" strip of spruce atop the SD10 soundboard? I have forgotten.

It is not really a rib. It covers a joint in the soundboard. The SD-10 used a soundboard cutoff bar. To make gluing the edge of the soundboard to that cutoff bar easier and more reliable the board was cut so it could be clamped more securely to the bar. Then the remaining small triangle portion was glued in and the joint was covered by a thin maple wood strip.

Next time you're sitting in front of one of these pianos follow that strip to the front edge of the board and look down just below the damper guide rail. You'll see a slight gap in the edge of the board.

As promised, here's another photo showing the top-ribs on the Bauer 6' grand, this time with all the wires & dampers removed for a better view:

This Bauer's design continues to present surprises. As you can see, the plate is a "full-perimeter" plate. The outer edge of the plate is not just a thin perimeter that sits on top of the soundboard dowels. The outer rim of the plate is a 6" deep "wall" of cast iron, bolted to the rim all around, as well as bolted down to the board.

I removed all the strings, dampers, and all the plate bolts visible from the top, to allow me to lift the plate up & off the board and out of the piano. But it wouldn't budge. Even lifting with my crane & hook, it just wanted to lift the whole cabinet up with it, as if it was stuck or there was one bolt I missed still holding it down. Turns out there were quite a few bolts still screwed in...under the soundboard.

That 6" vertical wall of iron that forms the outer rim of the plate, has "tabs" on the bottom, small extensions in the plate's casting for a dozen bolts to screw the plate to the cabinet perimeter just under the soundboard:

In my 9' JB there were relatively low laminated maple strips in the shape of the bridges glued to the soundboard with cutouts for the ribs. The actual bridges were [s][/s]mounted on dowels that were fitted into holes drilled into the top of this strip and the bottom of the bridges. In the treble the bridge was probably 50 to 60 mm tall By the time it got to the low tenor it was more like 140 or 150 mm. The bass was even taller.

The ribs underneath the soundboard panel were not quite as deep as those in your picture.

Del, I've been unable to find any patents/diagrams in a Google search for "Julius Bauer" or "Bauer adjustable soundboard" or anything like that. The closest I've come is a patent by F. B. Long for an upright soundboard with adjuster on each corner: https://www.google.com/patents/US936789?...ved=0CDIQ6AEwAw

So if you can post the actual link to the patent diagrams you saw for J. Bauer, that would be great.

Meantime, I not seeing any extra adjustment devices on this Bauer. And yes, the bridges have notches cut to accommodate fitting over the ribs, but the bridges appear to be one piece, plus a cap. A bit of a pain actually, as my bass bridge has enough thin diagonal cracks running right through the bridge-pin lines, to make it borderline as to repairing the existing bridge cap or needing recapping. I've never done my own bridge recapping, always sent it out to Schaff's bridge-maker. But with the notch-outs across the bottom, I don't know if he can match this.

Del, I've been unable to find any patents/diagrams in a Google search for "Julius Bauer" or "Bauer adjustable soundboard" or anything like that. The closest I've come is a patent by F. B. Long for an upright soundboard with adjuster on each corner: https://www.google.com/patents/US936789?...ved=0CDIQ6AEwAw

So if you can post the actual link to the patent diagrams you saw for J. Bauer, that would be great.

The only patents I know of that were issued to Bauer listed "William M. Bauer" as the inventor. I'm not sure that particular feature was patented by Bauer, however. I thought I remembered it being described in one of his patents but I'd have to go back and read through them to be sure. When I have the time....

I just want to say that those pictures represent one of the most sexy piano designs I've seen in a very long time. There are sooooooooooooooo many things "right" with that design. Modern manufactures would be wise to take serious note!

Freelife, when you took the plate out, was it distorted at all from the internal tension like some pianos, or was it pretty much flat? From here, it appears the design is really well balanced: I imagine it was probably pretty straight/flat if it were to theoretically be laid flat on the floor?

What theoretical books say is that the ribbing is intended to install stress within the panel. (stress under the panel, between ribs and the underside of it, and stress on the outside, due to crowned shape.

this is somehow destructive to the panel itself with decades most probably

As we cannot know how where glued those ones it is very difficult to imagine.

Thanks for sharing that.

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The concept of the set screw to adjust crown seems okay, but looking at the patent drawings, I wonder about the execution. I'd love to see the actual product.

It looks to me that turning the set screw (16) would necessarily cause the screw (13) that fixes the soundboard (10) to outer strip (12) to tilt away from the setscrew as the outer strip moves inwards to increase crown. Either the screw will bend or it will unseat at the head slightly in the inset (into cast iron!). I'm guessing bend. If the screw were flat-head, with washers, and that hole slotted slightly to allow the inward movement caused by that set screw, no problem. I realize the amount of movement would be very slight to yield the crown, but that movement has to be accommodated somewhere and an inset screw of that type would seem to only allow the movement to occur with bending of the screw or tilting it out of the inset on one side at the head.

Also, what about the stresses on glue joints where (10), (11), and (12) meet, and what about compression deformation of 11 where it meets the flange when the induced tilt (if it can't slide as in a slotted screw hole) of (10), since one would assume this flange-to-strip joint by necessity is initially tight and without a gap.

To me, it seems a good idea not so neatly executed (at least in the patent drawings). I'd be interested in seeing if the final product accommodated movement better than the drawings do.

I think you did not get the location of the pushing bolt, which force the soundboard up without much problems with the screws, even if they warped a little that is not much a concern, but they probably do not suffer.

But the soundboard is somehow floating, with that system, hence may be the double ribbing

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It is critical that you call your Senators and Representatives and ask them to cosponsor S. 2587 and H.R. 5052. Getting your legislators to cosponsor these bills

I think you did not get the location of the pushing bolt, which force the soundboard up without much problems with the screws, even if they warped a little that is not much a concern, but they probably do not suffer...

It would be rather hard to not get the location of the pushing bolt, since it's numbered and referenced in the patent.

It's that warp in the screws I'd prefer to avoid, even if, to you, it's not much a concern. My point is that slots and flathead bolts would prevent that warping. However minor, it's simply unnecessary.

Consider that an adjustment might be made that warps those screws (and compresses that wood strip). Then that just perhaps the additional crown turns out to have negative affect and the tech wants to back off the adjustment--will those warped screws prevent movement back to the original position? Will that compressed upper strip contacting the flange conform to that flange, after it's been compressed out of its original shape?

I simply think that with better execution of the same idea you gain an advantage without inducing problems from a poor execution. That's my only point. The basic idea seems quite good but if I were going to incorporate such a feature, I'd rather it be better-engineered.

The concept of the set screw to adjust crown seems okay, but looking at the patent drawings, I wonder about the execution. I'd love to see the actual product.

It looks to me that turning the set screw (16) would necessarily cause the screw (13) that fixes the soundboard (10) to outer strip (12) to tilt away from the setscrew as the outer strip moves inwards to increase crown. Either the screw will bend or it will unseat at the head slightly in the inset (into cast iron!). I'm guessing bend. If the screw were flat-head, with washers, and that hole slotted slightly to allow the inward movement caused by that set screw, no problem. I realize the amount of movement would be very slight to yield the crown, but that movement has to be accommodated somewhere and an inset screw of that type would seem to only allow the movement to occur with bending of the screw or tilting it out of the inset on one side at the head.

Also, what about the stresses on glue joints where (10), (11), and (12) meet, and what about compression deformation of 11 where it meets the flange when the induced tilt (if it can't slide as in a slotted screw hole) of (10), since one would assume this flange-to-strip joint by necessity is initially tight and without a gap.

To me, it seems a good idea not so neatly executed (at least in the patent drawings). I'd be interested in seeing if the final product accommodated movement better than the drawings do.

If you were to remove the soundboard assembly—I did not—you would find that it behaves very much like a three-ply laminated (and rib-less) panel. The crown was forced into assembly in the press when the ribs were glued on. It is really quite a good idea, I think.

This could also be done with a three-ply wood veneer soundboard assembly but, to my knowledge, it has never been done. At least not commercially. I have tried to generate interest in the idea but, so far, without success.

In the 9’ JB that I had the inner rim was attached to the string frame much like it is shown in the patent drawing. The only difference I can see right off is that the underside of the string frame where the inner rim was seated was relatively narrow and appeared to be slightly curved. I did not remove the soundboard assembly so I don’t know this for sure but it wouldn’t be the first time an inventor left a few important details out of his application. I assumed this was to enable the top of the soundboard liner to rotate slightly when (if) the adjustment bolts were turned. In my piano I doubt they had been touched since the piano was originally built.

I played around with them some once I had the strings off of the string frame. They were adjusted to just contact the inner rim and, as far as I could tell, were doing nothing to add crown to the soundboard. When I backed the adjustment bolt—applying more force against the inner rim—out they did, indeed, force additional crown into the system. I didn’t go too far with this. I was only interested in finding out if they would do anything at all. Since there was already more than adequate crown in the system I ended up returning them to roughly the original settings.

(All of this is from memory. I sold the piano sometime in the mid-1980s so please forgive me if some details are a bit fuzzy.)ddf

If you were to remove the soundboard assembly—I did not—you would find that it behaves very much like a three-ply laminated (and rib-less) panel. The crown was forced into assembly in the press when the ribs were glued on. It is really quite a good idea, I think....

I like the idea of such a panel and realize it'd act like a three-ply laminated panel, with crown glued in. Probably would work well enough to make all but unnecessary that crown adjustment mechanism that I think might have been engineered a little better. With that panel, I doubt the shortcomings of the crowning adjustment system ever became an issue.

If you were to remove the soundboard assembly—I did not—you would find that it behaves very much like a three-ply laminated (and rib-less) panel. The crown was forced into assembly in the press when the ribs were glued on. It is really quite a good idea, I think....

I like the idea of such a panel and realize it'd act like a three-ply laminated panel, with crown glued in. Probably would work well enough to make all but unnecessary that crown adjustment mechanism that I think might have been engineered a little better. With that panel, I doubt the shortcomings of the crowning adjustment system ever became an issue.

That was pretty much my thinking. The crown adjustment feature wouldn't work on a soundboard system that was less stiff and it wasn't necessary on a soundboard system that was this stiff.

I think you did not get the location of the pushing bolt, which force the soundboard up without much problems with the screws, even if they warped a little that is not much a concern, but they probably do not suffer...

It would be rather hard to not get the location of the pushing bolt, since it's numbered and referenced in the patent.

It's that warp in the screws I'd prefer to avoid, even if, to you, it's not much a concern. My point is that slots and flathead bolts would prevent that warping. However minor, it's simply unnecessary.

Consider that an adjustment might be made that warps those screws (and compresses that wood strip). Then that just perhaps the additional crown turns out to have negative affect and the tech wants to back off the adjustment--will those warped screws prevent movement back to the original position? Will that compressed upper strip contacting the flange conform to that flange, after it's been compressed out of its original shape?

I simply think that with better execution of the same idea you gain an advantage without inducing problems from a poor execution. That's my only point. The basic idea seems quite good but if I were going to incorporate such a feature, I'd rather it be better-engineered.

The distance the bolt need to make to gain crown in the panel is incredibly small.It was computed on this forum a few years ago. Showing how stiff the belt and plate assembly must be to avoid loosing crown. And why the glue may not give any deformation, in ribs and around the perimeter.

It work both sides.

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[quote=Olek]The distance the bolt need to make to gain crown in the panel is incredibly small...[/quote]

I am aware of that. It's precisely this reason I think such a system, if it's going to work properly as intended, ought allow for *precision* movement, and precise locking and unlocking of the position, and not anything that introduces potential slop as with bent screws or screws unseated from their recess. Precision would be easy enough to incorporate in the design.

I'm also interested in why Del said it would not work as well with other boards. I think the basic idea is good and think good provisioning for some stiffness in the edges of the board and careful placement of pressure-receiving points would allow it work on other more lightly-ribbed board, since the required movement *is* so small.

Del, is it that you think a lighter board would simply compress under the additional downbearing as additional crown is induced?

Why would not work with a lighter soundboard, Del? You mean it would only deform on its edges?

I didn't say "lighter" I said "less stiff". As in, more flexible. The adjustment feature depends on the parameter of the soundboard assembly being stiff enough to support crown in the middle -- along the bridge line. A more flexible system would simply bend.

It would be possible, of course, to build a soundboard assembly with equal stiffness and less mass.

I'm also interested in why Del said it would not work as well with other boards. I think the basic idea is good and think good provisioning for some stiffness in the edges of the board and careful placement of pressure-receiving points would allow it work on other more lightly-ribbed board, since the required movement *is* so small.

Del, is it that you think a lighter board would simply compress under the additional downbearing as additional crown is induced?

I didn't say "lighter", I said "less stiff". There is a difference.

A conventional soundboard system is relatively flexible around its parameter. A mechanism such as this would simply bend the assembly and accomplish nothing.

The same problem exists with the notion of beveling the inner rim and belly rail to "form crown" or "support crown." The parameter of the assembly is so flexible that all that is accomplished is to introduce a warp in the assembly at the edge of the board just in from the inner rim.

I realized you'd said "less stiff" rather than "lighter" right after I hit "submit". (That's when I discovered the edit function wasn't working this morning.)

Originally Posted By: Del

A conventional soundboard system is relatively flexible around its parameter. A mechanism such as this would simply bend the assembly and accomplish nothing.

The same problem exists with the notion of beveling the inner rim and belly rail to "form crown" or "support crown." The parameter of the assembly is so flexible that all that is accomplished is to introduce a warp in the assembly at the edge of the board just in from the inner rim.

ddf

So you think it's essentially the same result discussed around and around at PTG's forum of what happens to a board with "compression crown"? I suppose my own mind wants to imagine that if a board were *just* stiff enough, Bauer's idea might work, but that just goes to the point you made earlier about if a board *is* stiff enough (and properly crowned by ribbing [or even lamination] in the first place, it's not going to need "adjustment".

What about if the board were made of something other than spruce, like carbon fiber, that might not compress and might not be as susceptible to uncontrolled warp?

I suppose what I'm interested in here is the concept of such a fine adjustment of crown as Bauer might have intended. It'd be interesting to be able to hear, in a single piano, the effect on tone, with an ability to change that one variable while all others remain the same.

While I know others are sort of playing around with the concept, I find the idea of carbon fiber boards most fascinating. I wonder if it can go further in to plate design and being used as a "string frame" as Del usually refers to it. A concert grand that doesn't weigh a half ton might be extremely feasible.

While I know others are sort of playing around with the concept, I find the idea of carbon fiber boards most fascinating. I wonder if it can go further in to plate design and being used as a "string frame" as Del usually refers to it. A concert grand that doesn't weigh a half ton might be extremely feasible.

Richard Dain (Hurstwood Farm, England) has done just that. Google "Richard Dain." for all kinds of interesting places to go.

William Bauer was a very innovative piano thinker. His patents are available for reading online, which he makes his claims.Also, I have some pics of the inside of the factory on my website that I got from a descedent of the finisher.http://antiquepianoemporium.com/bauer-julius/

...so, I guess that is a double decker bridge?!? I'm really curious as to how that sounds!!! That looks like it might be functioning somewhat like a sound post in a violin...that is interesting, no? I don't really have a mental reference as to how to predict that kind of sound. Any ideas? If that indeed does work, then a double layered soundboard, using those kinds of wooden connections in holes through the top level of the soundboard, could be a possibility. Producing a high and a low functioning soundboard separately is much easier (i.e., what is good for the bass, is not for the treble).

...so, I guess that is a double decker bridge?!? I'm really curious as to how that sounds!!! That looks like it might be functioning somewhat like a sound post in a violin...that is interesting, no? I don't really have a mental reference as to how to predict that kind of sound. Any ideas? If that indeed does work, then a double layered soundboard, using those kinds of wooden connections in holes through the top level of the soundboard, could be a possibility. Producing a high and a low functioning soundboard separately is much easier (i.e., what is good for the bass, is not for the treble).

Not everything was perfect in this design. That soundboard assembly is rather heavy and stiff as is the bridge assembly.

I don't have the scaling from my 9' JB in my computer (or, if it is, I can't find it) but as I recall the tensions were high even for a 9' piano. I lowered the tensions some to free up the system at the expense (probably) of some "power" but it improved the tone quality and the dynamic range. Since the piano was going into a private home the power loss -- if, indeed, there was one -- was of no consequence. The piano was still adequately loud for any mortal ears.

The two biggest problems with the overall design were cost and weight. This had to be one of the most expensive pianos in the world to build. And it weighed approximately twice as much as a more conventional grand of the same size.

The two biggest problems with the overall design were cost and weight. This had to be one of the most expensive pianos in the world to build. And it weighed approximately twice as much as a more conventional grand of the same size.

ddf

I still have bad memories from putting that piano on its side in preparation for being picked up by the Baldwin truck. How did you talk me into that?

Estonia where building very stiff grand concert pianos too.Everything seemed to be enlarged , up to hammer shanks at 136mm length

Forget string plane height ! the action had to be surelevated on wooden blocks in order to use 60 mm bore on meium hammers !

Lot of sustain, assurely, but the treble sloped own progressively to a somewhat non manipulable tone with very limited ynamics and more foundamental than partials

One of those 80's grands where owned by a Gallish pianist I know ,and put at work by the Buethner restoration workshop in ENgland, he told me they suppressed one rib on 2 +- (they probably made a new soundboard, an correcte the 250 mm string height)

Edited by Olek (09/07/1405:30 AM)

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The two biggest problems with the overall design were cost and weight. This had to be one of the most expensive pianos in the world to build. And it weighed approximately twice as much as a more conventional grand of the same size.

ddf

I still have bad memories from putting that piano on its side in preparation for being picked up by the Baldwin truck. How did you talk me into that?

You got even. During transit the piano tipped over and landed on top of my bicycle. Never saw a flatter bike....

I thought a bit more about the pictures of the double-decker upright bridge. It is intriguing: it probably gives the piano more acoustical ambience (i.e., the opposite of a clear focused percussive attack sound). For a home piano, this could have been a step in the right tonal direction.

However, I am guessing that if bridge-tilt is a real thing, then this probably one of the worst examples of something like that. No?

BTW, I haven't observed bridge tilts in pianos, but I've also never gone looking for it either. Has anyone actually measured this? Is there a method?

I'm still trying to figure out what I think the ideal side bearings at the bridge should be (i.e., the angles and length between). Not enough, at it can create falseness, too much...maybe bridge tilting gets worst?!? Bridge-tilt happens predictably with the string instruments--it makes sense it would/could happen with the piano as well.